Our Earth has changed more dramatically in the 20th Century then in any other time period previous. During this time the health of our planet has also been both harmed and improved in dramatic ways. Two examples are that in this century, we have produced more air pollution then ever before, but our nature conservation efforts are working. Based on that type of logic, it is usually very easy for a scientist to tell if a particular change in our environment during the 20th Century, was good or bad for our planet. That is where population growth comes in and breaks this idea. Is population growth good or bad for our world? This is a question which scientists around the world have been debateing about for decades. The purpose of this essay will address that question. It will also talk about the future growth rate of our world's population, what if any relationship can be drawn from over population and the GNP and literacy levels in a country, what types of population control measures the four largest countries use, and finally determine if there are any population problems and find solutions for them. Despite extensive population control measures, the country with the largest population is China. In fact China contains almost one-fourth of the world's people at around 1.2 billion. During the 1950's the population grew at a rate of 2% per year. The rate of growth slowed to 1.3% by 1990, in part due to population control measures. China's population control measures are based around a creul policy allowing parents only one child. This policy has led to higher levels of abortion, sterilizations, and inficide than in any other country in the world. The dramatic declines in China's population growth rate have however taken place well before the one child policy went into effect in 1979. This further confuses experts who study population and try to determine why population rates flucuate. Some of these experts suggest that aside from the one child policy China's growth rate might have decreased from 2.0 to 1.3 percent because of major improvements in infant mortality rates. Thus parents had more confidence that their children would live to maturity. Also, as China has moved to become a more industrialized country families have chosen to reduce family size. For example in our country 200 years ago families were large because the more kids a family had the more successful the farm would be. Those are a few reasons the population rate in China might be lower than in years previous and continue to slow down.